Magnetic resonance imaging in the evaluation of persistent carpal tunnel syndrome.

Magnetic resonance imaging was used to assess nine median nerves in the wrists of seven patients who had signs and symptoms of persistent compressive median neuropathy despite previous carpal tunnel release. Intraoperative findings were then correlated in eight surgically treated cases with both MRI findings and postoperative results. Magnetic resonance imaging suggested a potential abnormality in each of eight operative cases. These findings correlated very well with both intraoperative observations and postoperative results, which indicated that some abnormality involving either the median nerve or the transverse carpal ligament had been present in all cases. Magnetic resonance imaging proved to be a sensitive and specific tool in the evaluation of persistent postoperative median nerve compression.